MDAC 2.5 SDK - ODBC Programmer's Reference
Chapter 17: Programming Considerations
Because SQLCloseCursor is almost the same as SQLFreeStmt with SQL_CLOSE, the Driver Manager does not map this function. Replacement functions are mapped so that existing ODBC 2.x applications can easily move to ODBC 3.x by using the new functions. Such a move makes it easier for such applications to begin using new ODBC 3.x functionality inside of conditional code in a modular fashion. SQLCloseCursor does not represent any new functionality. An application does not gain any advantage by moving to SQLCloseCursor from SQLFreeStmt with SQL_CLOSE.